In addition to the plasma membrane, plant cells have a rigid cell wall too. The plasma membrane is selectively permeable allowing only certain particles to pass. As the membrane is composed of lipids, charged or polar particles are not passed across the uncharged lipid barrier on its own and would require carriers. Neutral particles having no charge will pass easily
Transportation occurs through two modes:
Active transport – requires energy such as a sodium channel
Passive transport – do not require energy such as osmosis and diffusion
Water passes the membrane through osmosis. Aquaporins(channels) of the cell membrane carry out the process. As seen in diffusion, water also follows the concentration gradient. If the concentration outside the cell is more than the inside, water will flow. Osmosis exhibits selective permeability of the membrane.